Acute appendicitis is one of the most common surgical emergency making up to 10%of all emergency abdominal surgeries. It is difficult to diagnose acute appendicitis in young, elderly  patients and female of reproductive age group because they have atypical presentation. No investigation is fool proof combination of clinical history, physical examination and laboratory studies lead to development of several scoring systems. Apart from ALVARDO and modified ALVARDO score Anderson score (appendicitis inflammatory response score ) was developed with better sensitivity and specificity for diagnosis of appendicitis.